Swivel support for shovel boom



Oct. 17, 1961 Filed June 5, 1958 R. M. GRIFFITH 3,004,674

SWIVEL SUPPORT FOR SHOVEL BOOM 3 Sheets-Sheet 1 Oct. 17, 1961 R. M.GRIFFITH SWIVEL SUPPORT FOR SHOVEL BOOM Filed June 5. 195s- 3Sheets-Sheet 2 Nul N .Sl

Robert M. Griff/fh INVENTOR.

Oct. 17, 1961 R. M. GRIFFITH SWIVEL SUPPORT FOR SHOVEL BOOM 3Sheets-Sheet 3 Filed June 5, 1958 Robert M. Griff/'fh 1N VEN TOR. wh. BY@ab uu/guay me!! UnitedStates Patent O f' Y 3,004,674 SWIVEL SUPPORT FORSHOVEL BGOM Robert M. Griffith, Prineville, Oreg. (P.0. Box 621,McCloud, Calif.) Filed June 5, 1958, Ser. No. '740,151 15 Claims. (Cl.212-425) This invention relates in general to new and usefulimprovenientsin shovel construction, and more particularly tol animproved shovel boom for use in conjunction with llog handling tongs.

At the present time conventional type shovels are being used in loghandling operations. Such shovels have mounted on the boom sticksthereof log handling tongs which are so constructed whereby they willgrasp the log and support the log for the necessary log handlingoperation'. However, there are many instances when it is necessary topick a log up from a pile with the result that a side twist is placed onthe log handling tongs. Such side twist is then transferred to the boomstick which causes a racking of the boom stick and a torsion or bendingmoment on the connection between the boom stick and the boom. Further,when the log is being moved about, any change of movement of the log,that-is acceleration orl deceleration ofthe log as itis swung, resultsin the racking ofthe boom stick. This is an undue strain for which theboom of a conventional shovelis not designed. As a result, the boomfails after a relatively short use and must be replaced or repaired at arelatively great expense to the owner. i

IIt is therefore the primary object tof this invention to provide animproved boom for shovels which is particularly adapted for use in a loghandling operation, the

boom including a swivel supportI for the boom stick whereby the boomstick is free to twist duringl thelog handling operation so that notorsion in the boom stick results nor are torsional or bending momentstransferred from the boom stick to the boom through the boom sticksupport,

Another object of this invention is to provide an improved boom forshovels to be used in log handling lopera tions, the boom including aboom support having slidably received therein a boom stick, the boomsupport supporting a swivel action of the boom stick as well as thesliding movement so that racking of the boom stick and the boom isprevented. .Y

'Still another object of this invention is to provide an improved boomconstruction for use in conjunction with shovels during a log handlingoperation, the boom construction including a swivel support for the boomstick, and there being provided a suitable crowd mechanism whereby theboom stick may be operated with respect to the boom in the normal mannerand at the same time the racking of the boom stick and the boom iseliminated.

Another object of this invention is to provide an improved crowdmechanism for use in conjunction with a swivelly mlounted boom stick,the crowd mechanism including a pair of cables connected to oppositeends of the boom stick and being anchored by means of a drive mechanismwhich will simultaneously foreshorten one of the cables while paying outthe other of the cables so that the boom stick may be moved in thedesired direction through the support thereof carried by the boom.

A further object of this invention is to provide an irnproved crowdmechanism for use in conjunction with swivelly supported boom sticks ofa shovel boom, the crowd mechanism including a rack on the boom stickand a pinion gear carried by the support for the boom .stick and engagedwith the rack whereby through the pinion gear and the rack the boomstick may be extended or retracted as is desired. f

These together with other objects and advantages which Patented Oct. 17,1961 ICC will become subsequently apparent reside in the details ofconstruction and operation as more fully hereinafter described, andclaimed, reference being hadto the accompanying drawings forming a parthereof, wherein like numerals refer to like parts throughout and inwhich: FIGURE 1 is a side elevational view of a shovel particularlyadapted for a log handling operation and shows the particular boomstructure which is the subject of this invention, the boom stick beingprovided with a -log handling tong assembly;

FIGURE 2 is an enlarged fragmentary sectional view taken substantiallyupon the plane indicated by the section line 2 2 of Figure 1 and showsthe specific details of the connection between the boom stick and theboom, as well as the crowd mechanism for retracting and extending theboom stick with respect to the boom;

FIGURE 3 is an enlarged fragmentary sectional view taken substantiallyupon the plane indicated by the section line 3 3 of FIGURE 1 and showsthe connection between the forward end of the boom stick and the loghandling tong assembly;

FIGURE 4 is an enlarged fragmentary sectional view taken substantiallyupon the plane indicated by the section line 4--4 of FIGUREl :and showsthe specific details of the swivel suppoit for the boom stick;

FIGURE 5 is an enlarged fragmentary vertical sectional view takenthrough a modified form of boom construction and shows the `specificdetails of another form of crowd mechanism;

FIGURE 6 is an enlarged fragmentary side elevational View of anotherform of boom assembly with portions of the boom thereof being brokenaway in order to illustrate the specific details of still another formof `crowd mechamsm; A Y

FIGURE 7 is an enlarged fragmentary sectional'view taken substantiallyupon the plane indicated by the'section line 7--7 of FIGURE 6 and showsfurther the details of the construction of the crowd mechanism;

FIGURE 8 is a fragmentary horizontal sectional View Von a large scaleshowing still another modified form of boom assembly, the View beingsimilar to FIGURE 2 and shows the specific details of the boom assembly;

-FIGURE 9 is an enlarged fragmentary sectional vie taken through theboom stick support of the boom assembly of FIGURE 8 and shows thevspecific details thereof;

FIGURE 10 is an enlarged fragmentary horizontal sectional view similarto FIGURE 8 and shows the details of still another form of boomassembly; and

FIGUIRE l1 is an enlarged perspective View of a boom stick 'supportingmember of the boom stick support of FIGURE 10. Referring now to thedrawings in detail, it will be seen that there is illustrated in FIGUREl a shovel which is re- .ferred to in general by the reference numeral10, and

which is particularly adapted for use in a log handling operation. Theshovel 10 includes a crane body 12 which has pivlotally connected to thelower forward part thereof the boom assembly which is the subject ofthis invention, the boom assembly being referred to in general bythereference numeral 1-4. The boom assembly 14 includes a boom 16 which ispivotly connected to the crane body Vas at 18 and which is provided atthe upper end thereof with suitable sheaves 20 over which there areentrained cables 22. The cables 22 are in turn entrained over sheaves,`24 carried by `an A frame 26 mounted on the train body 12 to effect theraising and lowering of the boom 16.

Carried by an intermediate part of the boom 16 VisV a boom sticksupport, which is referred to in general bythe reference numeral 28. Theboom stick support 28, in turn, supports a boom stick 30. Carried at theforward end of the boom stick 30 is a log handling tong assembly 32which in itself plays no part in the present invention.

In order that the log handling tong assembly 32 may he raised andloweredto the pivoting of the boom stick 30, there is provided a't the upperend of the boom stick 16 sheaves 34 over which thereis entrained a cable36. The cable 36 also passes over a sheave 38 carried 'by 'the yloghandling tong assembly. 32. The cable V36 terminates in the crane body120m one of the drums (not shown) thereof.

Referring now to FIGURE 2 in particular, it will b Vseen that the boom16 is formed of a pair of transversely spaced parallel boom membersllwhich` :are `conr`nected together at spaced intervals by transversemembers. The boom members V488 are illust-rated as being channel-shapedin cross-section, but may be of any desired configuration.

Referring now to FIGURE 4in particular, it will be seen that the boomstick support 28 includes an .outer fitting 42 which is rhollow andwhich `has extending .from opposite .sides thereof aligned trunions 44.The `tzt-unions 44 are rotatably journaled 'in suitable bearingassemblies 46 carried by the boom members 38. It is to be noted that theouter fitting 42 is spaced inwardly yof the boom members 38 for a reasonto be set 4forth in more detail hereinafter.

Extending generally vertically through the outer support fitting 42 arealigned pivot members 48 which are :disposed normal to the axis of thetrunnions 44. `Pivotally mounted on the pivot members 48 within theouter support fitting 42 is an inner support fitting 50. The innersupport fitting 50 is provided with a bore 52 therethrough. The hoornAstick 30 conforms in crossvsection to the bore 52 and is slidablyreceived therein;

From the foregoing -description of the boom stick support 28, it will beseen that the boom stick 30 is mounted for both sliding and rotationalmovement with respect piston (-not shown) to which there is connected anextensible piston rod 86. The piston rod 86 is conto the boom sticksupport 28 .and that the'boom :stick Y support 28 permits pivoting ofthe boom stick in a vertical plane passing through the boom 16 aswell asabout an axis lying within that plane. the 'boom stick 30 is swivelly.mounted with .respect to the boom 16 rso that racking thereof iseliminated.

Referring now to FIGURE .3 in particular, it will be seen that theforward end of the boom stick 30 is bifurcated `to provide a pair ofvertically spaced parallel plate portions 54. These plate .portions 54are suitably secured to a casting 56 of the log handling tong assembly32. Also extending through the plate portions 54 is 4a shaft formingmember 58 on which there is mounted a generally horizontally disposedsheave 60. 'Ihe sheave 60 is disposed intermediate the plate portions 54and is spaced therefrom -by means of spacers 62.

Referring once again to FIGURE 2 .in particular, it will be seen thatcarried by one of the transverse frame members is a sheave 64. Also, the`rear portion of the bucket stick (30 includes a pair l`of plateportions 66 similar to the plate portions 54 through which there passesa shaft forming member 68 supporting a sheave 70.

Anchored to the bucket stick support 28 as at 72 is one vend of a cable74. The cable 74 passes about Ythe sheave 70 and is entrained over asheave 76 which is rotatably journaled on one of the trunnions 44, as isbest shown in FIGURE 4. 'Ihe cable 74 then passes about the sheaves 64and is entrained over a sheave 78 carried by the other of the trunnions44, as is also best shown in FIGURE 4. The cable 74 then passes aboutthe sheave 60 and is finally anchored to the bucket stick support 28 asat 80.

Secured to one of the boom members 38 is a hydraulic motor of theextensible type, the hydraulic motor being referred to in .general Vbythe reference numeral 82 and includes a cylinder 84 on which there ismounted a nected to an intermediate part of the cable 74 intermediatethe sheaves 64 and 78 by means of a fitting 88. The hydraulic motor 82Vis of the double acting type and has connected lto opposite ends of thecylinder 84 thereof hydraulic lines .90 and 92 which fextend into thecrane body 12 and lare `connected to a suitable pressurized hydraulicsystem (not shown).

By extending or retracting lthe 'piston rod 86, the bucket stick 30 maybe extended or retracted with respect to the boom 1'6, as is desired.Thus the numerous sheaves described, the cable 74 and the fluid motor 82combine to form a crowd mechanism which is referred to in general by thereference knumeral 94. lThis crowd mechanism will `be operated bysuitable controls within the crane body 12.

At this time it is pointed out that Ythe log handling tong assembly 32is operated by a hydraulic system which includes a pair of hydrauliclines 96 and 98. rPhe hydraulic lines 96 and 98 pass through the bucketstick 30, as is best shown in FIGURE 4 and are connected to thepressurized .hydraulic system within the crane 4body 12.

Referring now to FIGURE 5 in particular, it will be seen that there isillustrated a slightly modified form of crowd mechanism which isreferred to in .general .by the reference numeral A100. I The crowdmechanism -100 is mounted lon a boom 102 which lis identical with theboom 16 and is connected to a-boom stick 104 which is identical with theboom stick l30. Also, the boom stick 104 is supported relative to theboom 102 by means of a boom stick support 1.06 which is identical to theboom stick support 28.

The boom 102 includes a pair of spaced parallel boom members 108 whichhave extending therebetween a shaft 110 which has the opposite endsthereof journaled in suitable bearing assemblies 112 carried by the boommembers 108. The shaft 110 has drums 1'14 and 116 mounted thereon.

Carried by the boom members 108 yand extending therebetween is a plate118. The plate 118 has mounted thereon a hydraulic motor 120 of therotary type which includes a drive shaft 122 'on which there is mounteda sprocket '124. Aligned with the sprocket l124 is a sprocket 126.carried by an input shaft 128 of a reduction Vgear unit 130. Connectingtogether the sprockets 124 and 126 is a drive chain 132. VThe vreductiongear unit 130 is mounted on the plate 118.

The reduction gear unit 130 also includes an l.output shaft '134 onwhich there is mounted a sprocket36. 'The sprocket 136 is aligned withthe sprocket 138 and is drivingly Vconnected thereto by ymeans `of adrive 'chain 140.

In order that the hydraulic motor 120 may be driven, there is providedsuitable .hydraulic lines VV142 which will be connected to thepressurized hydraulic suppply of the crane body 12. Suitable controlswill be .provided within the frame body 12.

Reeled yon the drum 114 is la cable 144 which corresponds to the forwardpart of the cable 74. Reeled on the drum 116 is a cable l146 whichcorresponds to the rear half of the cable 74. Thus the crowd mechanism100 'will operate lin the same general manner as the crowd mechanism 94,but will be driven by a :different type of drive mechanism.

Referring lnow to FIGURES 6 and 7 in particular, it will be seen thatthere is illustrated a modified form of boom assembly which is referredto in general by the reference numeral 148. The boom assembly 148includes a boom 150 which is identical with the boom 16. Carried by theboom 150 is a boom stick support 152. The boom stick support 152 in turncarries `a boomstick 154. e

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The boom stick support 152V is very similar to the boom stick support 28and includes an outer support fitting 156 which will be identical withthe outer support fitting 42.V Pivotally mounted Within the outersupport fitting 152 by pivot members identical to pivot members 48 inFIGURE 4, is an inner support tting 158, the bottom pivot member headbeing visible in FIGURE 7, while the heads of both pivot members beingvisible in FIGURE 6. The inner support fitting 158 differs from theinner support fitting 50 primarily in that it is of a greater4 lengththat the inner support fitting 50 and in lieu of a bore 52 it isprovided with a partial bore 160, as is best shown in FIGURE 7, whichopens into an enlarged opening 162in the bottom part of the innersupport fitting 158.

The boom stick 154 differs from the boom stick 3i) only in that there issecured to the underside thereof an elongated rack 164. It is thepurpose of the opening 162 to provide clearance for the rack 164 andthus provide for limited rotation of the boom stick 160 relative to theinner support fitting 158.

Extending transversely `of the inner support fitting 158 and supportedthereby is a shaft 166. The shaft 166 is provided with a pinion gear168. The pinion gear 168 is meshed with the rack 164 to effect theextension and retraction of the boom stick 160 as desired. The rack 164has a relatively wide circumferential eX- tent so as to permit a slightrotation of the boom stick 160 within the inner support fitting 158.

In order that the shaft 166 may be driven, there is mounted on the upperrear part of the inner support fitting 158 a reduction gear unit 170 towhich there is connected a rotary hydraulic motor 172. The reductiongear unit 170 is provided with an output shaft 174 disposed parallel tothe shaft 166. The output shaft 174 carries a sprocket 176 which isaligned with a sprocket 178 on the shaft 166. The sprockets 176 and 178are connected together by a drive chain 180.

The hydraulic motor 172 is provided with suitable hydraulic fluid supplylines 182. The hydraulic iiuid supply lines 182 will. be connected tothe pressurized hydraulic supply system of the cranebody 12. Suitablecontrols will be provided to facilitate the operation of the crowdmechanism, which crowd mechanism will be referred to in general by thereference numeral 184.

Referring now to FIGURES l and ll in particular, it will be seen thatthere is illustrated a modified form of boom stick support which isreferred to in general by the reference numeral 186. The boom sticksupport 186 may be mounted in the boom 16'in the manner described abovewith respect to the boom stick support 28. However, the construction ofthe boom stick support 186 differs from that of the boom stick support28.

The boom stick support 186 includes a two-piece outer support fitting188 which is` provided with suitable trunnions 190 which journal theouter support fitting 188 in the boom 16. The internal construction ofthe outer support fitting 188 is such to provide a partial sphericalsocket 4192 inV which there 'is positioned a partial spherical member194 which forms a part ofthe inner support fitting 196. The innersupport fitting 196 is best illustrated in FIGURE ll and includes anelongated sleeve portion 198 through which the boom stick 200 passes. Atthis time it is pointed out that the boom stick 200 is illustrated asbeing square and the sleeve 198 as having a square cross-sectionalopening therethrough. It is not necessary that the boom stick 200 rotaterelative to the inner support fitting 196. However, the cross-section ofthe boom stick 200 may be that desired.

The crowd mechanism utilized in conjunction with the boom stick support186 may vary as desired and may be any one of those illustrated inFIGURES 2, and 6.

Referring now to FIGURES 8 and 9 in particular, it will be seen thatthere is illustrated a modified form of boom assembly which is referredto in general by the reference numeral 202. The boom assembly 202utilizes a boom identical with the boom 16. The boom assembly 202,however, utilizes a modified form of boom support 204 and a modifiedform of boom stick The boom stick support` 204 includes an outer supportfitting 208 which is identical with the outer support fitting 188. Theouter support fitting 208 is suitably journaled in the bearing units 46of the boom 16. Swivelly` mounted in the outer support fitting 208 .is amodified form of inner support fitting 210. The inner support fitting210 includes a generally spherical par-t 212 in which there is formed apair of sleeve portions 214. VThe sleeve portions 214,have.extendingtherebetween a shaft 216 on which there are journaled sheaves 218 and220'which correspond to -the sheaves 78 and-76, respectively.'

The boom stick 206 includes at pair of spaced parallel members 222 whichare connected together at their rear ends by a member 224 and which havetheir forward ends connected to` the log handling tong assembly32. Thesections 222 are slidably disposed in the sleeves 214, as is bestillustrated in FIGURE 9.

The member 224 is provided with a shaft 226 which carries a sheave 228.The sheave 228 Vcorresponds to the sheave 70. i, 2 i

Connected to the bottom 16 'andv theboom stick 206 is a crowd mechanismwhich is referred to in general by the Ireference numeral 230 and which,with the exception of the particular placements of the sheaves 218, 220and'228, is identical Vto the crown ,mechanism of FIG- UREV 5.Accordingly, a further description of the crowd mechanism is believed tobe unnecessary.

From the foregoing description of the present invention, it will be seenthat there have been devised several forms of boom assemblies whichinclude various forms of crowd assemblies, which boom assemblies aresuch in nature whereby pivoting and twisting of thebooin stick ispermitted with respect to the boom in order to prevent racking of theboom stick and the-connection between the boom stick and the boom. Also,the crowd mechanisms are of such a nature wherebythe boom stick may beextendedY and `retracted as is necessary in the operation thereof.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly, all suitable modificationsand equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

vWhat is claimed as new is as follows: Y n

1. A log handling boom assembly for shovels, said boom assemblycomprisingva boom, a support tting mounted on said boom intermediate theVends thereof, a boom stick supported by said support fitting includingmeans for universally pivotally mounting and slidably receiving saidboom stick while permitting free lateral displacement thereof, and crowdmeans carried by said support fitting and said boom stick for advancingand retracting said boom stick through said support fitting.

2. A log handling boom assembly forshovels, said boom assemblycomprising a boom, a support fitting mounted on said boom intermediatethe ends thereof, a boom stick supported by said support fittingincluding means for universally pivotally mounting and slidablyreceiving said boom stick while permitting free lateral displacementthereof, and crowd means carried by said support fitting and said boomstick for advancing and retracting said boom stick through said supportfitting, said crowd means including a hydraulic drive unit.

3.A log handling boom assembly for shovels, said boom assemblycomprising a boom, a support fitting mounted on said boom intermediatethe ends thereof,V a boom'stick supported by said support fitting forsliding and pivotal movement, and crowd means carried by said supportfitting and said boom stick for advancing and retracting `said boomstick through said support fitting, said support fitting includinganouter support fitting and first support means mounting said outersupport fitting for pivotal movement in a vertical plane passing throughsaid boom, an inner support fitting, second support means pivotallymounting said inner support fitting for pivotal movement relative tosaid outer support fitting.Y

4. A log handling boom assembly for shovels, said boom assemblycomprising a boom, a support fitting mounted on said boom intermediatethe ends thereof, a boom stick supported by said support fitting forsliding and pivotal movement, and crowd means carried by said supportfitting and said boom stick for advancing land retracting said boomstick through said support fitting, saidsupport fitting including anouter support fitting and first support means mounting said outersupport fitting for pivotal movement in a vertical plane passing throughsaid boom, an inner support fitting, second support means pivotallymounting said inner support fitting for pivotal movement relative tosaid outer support fit-ting, said inner support fitting including asleeve portion, said boom stick corresponding in cross-section to saidsleeve portion and slidable therethrough.

5. The combination of claim 4 wherein said crowd means includes a rackon said boom stick and a drive pinion supported by said support fitting.t

6. A log handling boom assembly for shovels, said boom -assemblycomprising a boom, a support `fitting mounted on said boom intermediatethe ends thereof, a boom stick supported by said support fittingincluding means for universally pivotally mounting and slidablyreceiving said boom stick while permitting free lateral displacementthereof, and crowd means carried by said support fitting and said boomstick for advancing and retracting said boom stick through said supportfitting, said crowd means including a pair ofcables,'one of said cablesbeing connected to one end of said boom stick, the other of said cablesbeing connected to the opposite end of said'boom stick, anddrive meansconnected to said cables for simultaneously paying out on one of saidcables while reeving in on the other.

7. A log handling boom -assembly for shovels, said boom assemblycomprising a boom, a support fitting mounted on said boom intermediatethe ends thereof, a boom stick supported by said support fittingincluding means for universally pivotally mounting and slidablyreceiving said boom stick While permitting free lateral displacementthereof, and'crowd means carried by Vsaid support fitting and said boomstick for advancing and retracting said boom stick through Vsaid supportfitting, said crowd means including a pair of cables, one of said cablesbeing connected to one end of said boom stick, the other of said cablesbeing connected to the opposite end of sai-d lboom stick,and drive meansconnected to said cables for vsimultaneously paying out on one of saidcables while reeving in on the other, said -drive means being mounted onsaid boom. Y

8. AAlog hand-ling boom assembly for shovels, said boom assemblycomprising `a boom, a support 'fitting mounted on `said boomintermediate the ends thereof, a boom stick supported by said supportfitting including means 'for universally pivotally mounting and slidablyreceiving said boom stick while permitting free lateral displacementthereof, and crowd means carried by said support fitting and said boomstick for advancing and retracting said boom Lstick through said supportffitting, said crowd means including arpair of cables, one of saidcables being connected to one gend of said boom stick, the other of saidcables being connected to the opposite end of said boom stick, and drivemeans connected to said cables for simultaneously paying out `on oneV ofsai-d cables 'while reeving in on the other, said support lfittingincluding trunnions extending transversely of said boom .8 sheavescarried by said trunnions, said cables passing over said trunnions, saiddrive means being mounted on said boom. i'

9. A loghandling boom assembly for shovels, said boom assemblycomprising a boom, a support fitting mounted on said boom intermediatethe ends thereof, a boom stick supported by said support fitting forsliding and pivotal movement, and .crowd means carried by said supportfitting and said boom stick for advancing and reti-acting said boomstick through said support fitting, said support fitting including anouter support fitting and first support means mounting saidouter supportfitting for pivotal movement in a vertical piane passing through saidboom, an inner support fitting, second support means pivotally mountingsaid inner support fitting for pivotal movement relative to said outersupport fitting, said second support means being in the formk of auniversal swivel fitting. t

l0. A log handling boom assembly for shovels, said boom assemblycomprising a boom, a support fitting mounted on said boom intermediatethe ends thereof, a boom stick supported by said support fittinguniversally pivotally mounting and slidably receiving said boom stickwhilel permitting free lateral displacement thereof, and crowd meanscarried by said support fittingA and said boom stick for advancing andretracting said boom stick through said support fitting, said crowdmeans including a drive unit mounted on said boom.

l1. A log handling boom assembly for shovels, said boom assemblycomprising a boom, Va support Vfitting mounted on said boom intermediatethe ends thereof, a boom stick supported by said support fitting forsliding and universal pivotal movement, and crowd means carried by saidsupport fitting and said boom stick for advancing and retracting saidboom stick through said support fitting, said support fitting includingan outer sup port fitting and rst support means mounting said outersupport fitting for pivotal movement in a vertical plane passing throughsaid boom, an inner support fitting, secondsupport means pivotallymounting said inner support fitting for pivotal movement relative tosaid outer support fitting, said crowd means including a pair of cables,one of said cables being connected to one end of said boom stick, theother of said cables being connected to the opposite end of said boomstick, and drive means connected to said cables for simultaneouslypaying out on one of said cables while reeving in on the other.

12. A log handling boom assembly for shovels, said boom assemblycomprising a boom, a support fitting mounting on said boomV intermediatethe ends thereof, a boom stick supporte/:l by said support fitting forsliding and pivotal movement, and crowd means carried by said supportfitting and said boom stickfor advancing andretracting said boom stickthrough said support fitting, said supportfittingY including an outersupport fitting and first support means mounting said outer supportfitting for pivotal movement in a Vertical plane passing through saidboom, an inner support fitting, a second support means pivotallymounting said inner support fitting for pivotal movement relative tosaid outer support fitting, said vsecond support means being in the form.of a universal swivel fitting, `said crowd means including a pau' ofcables, one of said cables being connected to one .end of said boomstick, the other of said cables 'being ,connected to the opposite'endsof said boom stick, and `drive means connected to -said cables forsimultaneously paying out on one of said cables while reeving in on theother.

13. A log handling boom assembly for shovels, said boom assemblyVcomygnising a boom, a support fitting mountingV on said boomintermediate the ends thereof, a boom stick supported by said ysupport`fitting for sllding and pivotal movement, .and Vcrowdmeans carried -bysaid support fitting and said boom stick for advancing and retractingsaid 'boom 'stick through said, support fitting, said support fittingincluding an outer support titting for pivotal movement in a verticalplane passing through said boom, an inner support iitting, a secondsupport means pivotally mounting said inner support tting for pivotalmovement relative to said outer support itting, said second supportmeans being in the form oi a universal swivel tting, said crowd meansincluding a pair of cables, one of said cables being connected to oneend of said boom stick, the other of said cables being connected to theopposite ends of said boom stick, and drive means connected to saidcables for simultaneously paying out on one of said cables While reevingin on the other, said support fitting including trunnions extendingtransversely of said boom, sheaves carried by said trunnions, saidcables passing over said trunnions, said drive means being mounted onsaid boom.

14. A log handling boom assembly for shovels or the like, comprising aboom, a boom stick, supporting means mounted on said boom foruniversally pivotally mounting and slidably receiving said boom stickwhile permitting free lateral displacement thereof, and mechanismoperatively connected to said supporting means and boom stick foreffecting sliding movement of said boom stick relative to saidsupporting means.

15. The assembly as dened in claim 14, wherein said mechanism includesmeans anchored to said supporting means for effecting the slidingmovement of said boom stick and a power source mounted externally of theassembly for energizing said mechanism.

References Cited in the le of this patent UNITED STATES PATENTS Re.21,405 Stiehl Mar. 19, 1940 1,907,442 Rauch May 9, 1933 2,569,458Davidson Oct. 2, 1951

